1. Field of the Invention
The present invention relates generally to gas-fired chick brooders and, specifically, to improvements in gas-fired chick brooders which increases the efficiency of operation and the operational life of the brooder.
2. Brief Discussion of the Prior Art
Gas-fired chick brooders are well known embodiment and various embodiments have been patented over the years: See U.S. Pat. No. 3,429,306 issued to Thompson on Feb. 25, 1969; U.S. Pat. No. 3,505,976 issued to Miller on Apr. 14, 1970; U.S. Pat. No. 4,458,663 issued to Kanesaka on Jul. 10, 1984; and U.S. Pat. No. 4,614,166 issued to Maurice on Sep. 30, 1986. All of these brooders have in common a burner device which permits the mixing of air and gas, a combustion zone in the vicinity of a ceramic radiant which is heated thereby and, in turn, radiates heat thereby warming the surface below the brooder.
One particularly well known and commercially successful gas-fired chick brooder is manufactured by Shenandoah Manufacturing and is identified as a brooder heater Model SGB. A characteristic of this unit is that when supplied with an hourly flow of gas having approximately 45,000 BTU's, it provides appropriate heating to the floor located thereunder. This popular gas brooder is shown in FIG. 1 and indicated by arrow 10.
This prior art gas brooder comprises three main assemblies: the glow housing 12 comprising a burner mounting ring 14, a perforated glow housing 16, and a reflector pan 18; the radiant 20; and the burner 22. Gas, either liquid, natural gas (LNG) or propane, is supplied to the burner 22 by pipe 24. The gas/air mixture coming from burner 22 is shown by arrows 26 traveling through combustion volume 28 formed in the space between radiant 20 and the perforated glow housing 16.
As can be seen in FIG. 1, the perforations permit inflow of external air to the combustion volume for mixing with the gas and outflow of hot combustion by-products. While a substantial portion of this combustion byproducts flow passes through the perforations to the outside air thereby heating the perforated glow housing 16 to a radiant condition, a substantial amount of the gases travel upwards and are trapped in the vicinity of the junction between the perforated glow housing 16 and the reflector pan 18. Because hot gases rise, extremely high temperature concentrations are achieved at this junction.
While the radiant 20 made of pressed ceramic fiber is unaffected by this high temperature, the instability and non-uniformity in gas flow around the upper portion of the combustion volume 28 causes localized hot spots. This irregularity in heating of the metal junction between reflector pan 18 and perforated glow housing 16 results in warping of the metal such that the seal between upper lip 30 of the radiant and the reflector pan 18 is broken leaving a gap such as that shown in FIG. 2a.
Once such a gap has been created, the hot combustion gases 26 in combustion volume 28 will take the path of least resistance in traveling upwards and will tend to travel up through this opening. As a result, this portion of the reflector pan becomes even hotter, and as a result, warps even more. The ultimate result is a substantially warped reflector pan, a non-uniform gas flow rate around the perforated glow housing 16 and a non-uniform temperature distribution on the floor below the brooder.
Accordingly, in order to insure that minimal required temperatures are maintained under the brooder, a greater amount of BTU's in the form of input gas supply is necessary rendering the brooder somewhat less than optimum in terms of operating efficiency.